<!DOCTYPE html>
<html lang="en">

    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>Document</title>
    </head>

    <body>
        <!-- 节点的优点 -->
        <div>我是div</div>
        <span>我是span</span>
        <ul>
            <li>我是li</li>
            <li>我是li</li>
            <li>我是li</li>
            <li>我是li</li>
        </ul>
        <div class="demo">
            <div class="box">
                <span class="erweima">×</span>
            </div>
        </div>

        <script>
            // 1. 父节点 parentNode
            var erweima = document.querySelector('.erweima');
            var box = document.querySelector('html');
            // 得到的是离元素最近的父级节点 如果找不到父节点就返回为 null
            console.log(erweima.parentNode);
        </script>
    </body>

</html>